Thank you for the feedback.
We are not sure that we will be able to beat Microsoft ComboBox in performance, as it is just a wrapper for the native combo. It is very hard for a managed control to beat performance of the native one, especially when offering several features which are not supported by the standard control (for instance, the ability for theming, animation, image in items support, allows for different items to have different height, gradients, etc). Excellent performance is one of our main goals and we are constantly working in this direction. Hopefully we will be able to be very close to the standard control with the next major version. Still, if performance is what you are after, you will be better off with using the regular MS controls.
As to the error, you will need to put the first line of code after
the DataSource of the combo is filled with data for the first time. In the "Form_Load" event handler you should have automatically generated a line of code that fills the table which gives data to the combo. After that line is executed you can call the code we gave you. Otherwise the combo will not have items and "Items(0)
" will throw an exception...
I hope this helps.
All the best,
the Telerik team